diff --git a/src/ert/shared/share/ert/forward-models/res/script/ecl_run.py b/src/ert/shared/share/ert/forward-models/res/script/ecl_run.py
index 57a3c2f3725..f54a6ec1d89 100644
--- a/src/ert/shared/share/ert/forward-models/res/script/ecl_run.py
+++ b/src/ert/shared/share/ert/forward-models/res/script/ecl_run.py
@@ -16,7 +16,7 @@
 from resdata.summary import Summary
 
 
-def await_process_tee(process, *out_files):
+def await_process_tee(process, *out_files) -> int:
     """Wait for process to finish, "tee"-ing the subprocess' stdout into all the
     given file objects.
 
@@ -316,7 +316,7 @@ def _get_log_name(self, eclrun_config=None):
                 logname_extension = "LOG"
         return f"{self.base_name}.{logname_extension}"
 
-    def execEclipse(self, eclrun_config=None):
+    def execEclipse(self, eclrun_config=None) -> int:
         use_eclrun = eclrun_config is not None
         log_name = self._get_log_name(eclrun_config=eclrun_config)
 
@@ -358,7 +358,12 @@ def runEclipse(self, eclrun_config=None, retries_left=2, backoff_sleep=None):
                 f.write("ECLIPSE simulation complete - NOT checked for errors.")
         else:
             if return_code != 0:
-                raise subprocess.CalledProcessError(return_code, self.sim.executable)
+                command = (
+                    self._get_run_command(eclrun_config)
+                    if self.sim is None
+                    else self._get_legacy_run_command()
+                )
+                raise subprocess.CalledProcessError(return_code, command)
 
             try:
                 self.assertECLEND()
diff --git a/tests/unit_tests/shared/share/test_ecl_run.py b/tests/unit_tests/shared/share/test_ecl_run.py
index d2917658a40..b10a55add43 100644
--- a/tests/unit_tests/shared/share/test_ecl_run.py
+++ b/tests/unit_tests/shared/share/test_ecl_run.py
@@ -408,6 +408,15 @@ def test_run_nonzero_exit_code(init_ecl100_config, source_root):
         erun.runEclipse()
 
 
+@pytest.mark.requires_eclipse
+def test_non_existing_eclipse_version(init_ecl100_config, source_root):
+    Path("FOO.DATA").write_text("", encoding="utf-8")
+    econfig = ecl_config.Ecl100Config()
+
+    with pytest.raises(KeyError, match="2079.3"):
+        econfig.sim("2079.3")
+
+
 @pytest.mark.requires_eclipse
 def test_run_api(init_ecl100_config, source_root):
     shutil.copy(
diff --git a/tests/unit_tests/shared/share/test_ecl_run_new_config.py b/tests/unit_tests/shared/share/test_ecl_run_new_config.py
index a1370b8c637..b04333dd30d 100644
--- a/tests/unit_tests/shared/share/test_ecl_run_new_config.py
+++ b/tests/unit_tests/shared/share/test_ecl_run_new_config.py
@@ -4,6 +4,8 @@
 import re
 import shutil
 import stat
+import subprocess
+from pathlib import Path
 from unittest import mock
 
 import pytest
@@ -178,6 +180,20 @@ def test_failed_run(source_root):
         erun.runEclipse(eclrun_config=eclrun_config)
 
 
+@pytest.mark.requires_eclipse
+@pytest.mark.usefixtures("use_tmpdir", "init_eclrun_config")
+def test_failed_run_nonzero_returncode(monkeypatch):
+    Path("FOO.DATA").write_text("")
+    econfig = ecl_config.Ecl100Config()
+    eclrun_config = ecl_config.EclrunConfig(econfig, "2021.3")
+    erun = ecl_run.EclRun("FOO.DATA", None)
+    monkeypatch.setattr("ecl_run.EclRun.execEclipse", mock.MagicMock(return_value=1))
+    with pytest.raises(
+        subprocess.CalledProcessError, match="Command .*eclrun.* non-zero exit status 1"
+    ):
+        erun.runEclipse(eclrun_config=eclrun_config)
+
+
 @pytest.mark.requires_eclipse
 @pytest.mark.usefixtures("use_tmpdir", "init_eclrun_config")
 def test_failed_run_OK(source_root):